You've got a number of problems here.

First off, if my eyes serve me right, those are 10g wires and a 13 cu in handy box. That's overfilling the box.

However if you rip out the whip to the cooktop, and put in a single device yoke, you'd still overfill the box.

Your electric cooktop installation is also making use of a grandfathered provision in the code that allows the grounded conductor to be used as the frame ground for the cooktop. You can't get away with that for a regular receptacle.

You'd need to replace that box with a larger one that would be legal (you need 14 cu in at least).

The next issue is you need a ground (you can not use the neutral). I can't see what is feeding that box. If it is armored cable or conduit that can legally serve as a ground, you are OK. If it is some form of other cable, you can either strip or recolor the white green on both ends (and terminate the white on the ground on the other end).

You need to put an appropriate sized breaker in for the receptacle you're using (15 or 20A most likely). It probably has a 30 now.

You should ask an electrician to come visit. THere's too much stuff I can't see with the little picture you show. It might be doable, it might not.

Ronnatalie,

Thank you for your reply. I'll have an electrician come out and save me the trouble. From your post, that's an easier option.

Any idea on how much something like this should cost? I'm Orange County, Ca. area.

Thanks so much!